Mixture of insoluble aminoanthraquinone dyes



Patented May 2, 1950 MIXTURE OF INSOLUBLE AMINO- ANTHRAQUINONE DYES PaulGrossmann, Binningen, and Walter Kern, Sissach, Switzerland, assignorsto Ciba Limited,

a Swiss firm No Drawing. Application September 14, 1948, Se-

rial No. 49,292. In Switzerland November 26,

Claims.

It is known that mixtures of dyestuffs are in some cases of advantagefor dyeing cellulose esters, for example, artificial silk or staplefibers of lower fatty acids of cellulose, such as cellulose butyrate,cellulose propionate and especially cellulose acetate, and also thecorresponding mixed esters. The use of mixtures of dyestuffs isindicated, inter alia, when the dyestuif mixture is required not forproducing a desired shade of color but when each of the dyestuffs to bemixed yields dyeings of the same tint or very similar tints, owing tothe fact that in many cases such a mixture yields a stronger tint thando the individual pure components of the mixture. This so-called mixtureeffect varies in strength in difierent instances. It naturally alsooccurs when by-products are formed in the manufacture of a singledyestufi and the by-products remain in the final dyestuif. Especiallypronounced mixture effects, that is to say those in which the resultingmixed dyeing is very considerably stronger than the dyeings obtainablewith the stronger-dyeing component of the mixture, are rare. Moreover, adyeing of enhanced purity is not to be expected by the use of mixtures,and in some cases, as would be expected, the mixed dyeing is more orless markedly dull.

The present invention is based on the observation that unexpectedly gooddyeings on cellulose esters are obtained by using mixtures of which thedyeing constituents consist mainly of l-(c-hydroxyethyl) amino 4phenylamino anthraquinone and l methylamino 4 phenylamino-.anthraquinone in finely divided form.

As cellulose esters to be dyed by the process of this invention theremay be used the known esters of cellulose with aliphatic acids of lowmolecular weight mentioned above. The fibers of some cellulose ethersand of superpolyamides, superpolyurethanes and superpolyesters are to beregarded as equivalents of fibers of cellulose esters, owing to theirsimilar properties.

The individual components of the mixture, namely 1 (fl-hydroxyethyl)-amino 4 phenylamlno anthraquinone and 1 methylamino-4-phenylamino-anthraquinone, are in themselves known and can be obtainedin various ways. It is of advantage to use them in the present processin a pure or relatively pure state. They may be converted in knownmanner into a finely divided condition prior to the dyeing process, forexample, by grinding with a dispersing agent such as sulfite cellulosewaste liquor, advantagefuric acid.

The two components may be mixed together before or during thepreparation of the dyebath. The relative proportions of the componentsmay vary within fairly wide limits, but it is of advantage to use notless than 20 per cent, preferably 25-50 per cent, of the component whichis present in lower proportion.

Dyeing may be carried out in the usual manner, for example, in aqueousdispersion with the addition of a wetting or dispersing agent such as asoap, an N-benzyl- -heptadecyl-benzimidazole sulfonic acid, acondensation product of taurine or methyl-taurine with a fatty acid, orthe like.

It is also of advantage to make a dyestuff preparation which containsthe two components mentioned above in the desired relative proportionsand in a state of fine dispersion and also contains a wetting ordispersing agent such as sulfite cellulose waste liquor, salts ofcondensation products from formaldehyde and naphthalene sulfonic acids,naphthenic acid salts, if desired with the addition of wetting agents,such as are mentioned above.

The following examples illustrate the invention, the parts being byweight:

Example 1 4 parts of 1 ([3 hydroxyethyl) amino- 4phenylamino-anthraquinone and 4 parts of 1 methylamino-4-phenylaminoanthraquinone are dissolved in 50 parts of sulfuric acid of per cent.strength. The solution is introduced into a mixture of parts of ice, 240parts of water and 55 parts of ammonia solution of 25 per cent.strength, stirred well and filtered. The filter residue is washedneutral and ground with about 12 parts of dried sulfite cellulose wasteliquor and the necessary quantity of water to form a dyestuif pastecontaining about 10 per cent. of the dyestufi mixture.

The paste so obtained produces on cellulose acetate artificial silk bluedyeings of great purity. It enables dark blue tints to be obtained whichare darker than those obtainable with the individual components of themixture or can be obtained therewith only by using a very much greaterquantity of dyestuff and then not in the same degree of purity.

Example 2 By using in the procedure of Example 1, 6 parts, instead of 4parts, of l-(p-hydroxethyl)-amino- 4-phenylamino-anthraquinone and 2parts, instead of 4 parts, of l-methylamino--phenylamino-anthraquinone,there are obtained similar 3 results which approach closely the goodresults obtained in Example 1.

Similar results are obtained by using 2 parts of 1 -(,8-hydroxyethy1)amino-e-phenylaminoanthraquinone and 6 parts ofl-methyiaminoiphenylamino-anthraquinone.

Example 3 10 parts of a paste of 10 per cent strength of finelydispersed l-(fl-hydroxyethyl) amino-ephenylaminoanthraquinone and 10parts of a paste of 10 per cent. strength of l-methylamino-4-phenylamino-anthraquinone are introduced into a solution of 6 parts ofthe sodium salt of N- benzyl,u-heptadecyl benzimidazole disulfonic acidin 200 parts of water at 30 0., and 3000 parts of water at 40 C. areadded while stirring well. 100 parts of well wetted cellulose acetateartificial sill: are entered at 40 C., the temperature is raised to 80C. in the course of hour, and dyeing is carried on at that temperaturefor one hour. The artificial silk is then rinsed and finished in theusual manner. A deep blue dyeingis obtained of great purity.

Example 4 The procedure is the same as that described in Example 3,except that 20 parts of a dyestuii paste are used containing 10 percent. of the dyestuii mixture and prepared as described in Example l or2. Very similar results are ob tained.

It is to be understood that the amount of dispersing agent contained inthe dyestuii preparations is not critical and may range from one tenthto many times the combined weight of the two dyestuffs. The dispersingagent may be omitted altogether if care is taken that, nevertheless, thedyebath prepared with the prepara tion contains the dyestuffs in finelydispersed condition.

If desired, the dyestuff preparations may be aqueous pastes or thinlyliquid dispersions or they may be dried, for example in an atomizer,especially if the amount of dispersing agent is not too low.

It is further to be understood that acetate rayon dyes, other than thosespecified above, may

be present as impurities or purposely added to the preparations in minoramounts, for example if not all of the beneficial effects of the presentinvention are required, or if the dyes added do not interfere therewith.

What we claim is:

1. A dyestuff preparation in which the dyeing constituent consistsmainly of a mixture or" 1-([3- hydroxyethyl) aminol-phenylaminoanthraquinone and 1-methylamino-4-phenylaminoanthraquinone in a finelydivided and dispersible condition and in relative proportions rangingfrom about 4:1 to 1:4, the said anthraquinone compounds beingsubstantially free from impurities possessing afiinity for acetaterayon.

2. A dyestuii preparation containing a dispersing agent in which thedyeing constituent consists mainly of a mixture of l-(B-hydroxyethyl)amino 4 phenylaminoanthraquinone and 1-methyl-amino-4-phenylaminoanthraqulnone in a finely divided anddispersible condition and in relative proportions ranging from about 4:1to 1:4.

3. A dyestuif preparation containing a dispers- 3 ing agent in which thedyeing constituent consists of a mixture of lJB-hydroxyethyl)-aminophenylaminoanthraquinone and 1methyl-amino-'i-phenylaminoanthraquinone in a finely divided and dispersible conditionand in approximately equal quantities.

A dyestuif preparation containing a dispersing agent in which the dyeingconstituent consists of a mixture of l-(B-hydroxyethyl) -amino- 4phenylaminoanthraquinone and l methylaminoA-phenylaminoanthraquinone ina finely divided and dispersible condition and in relative proportionsranging from about 4:1 to 1:4, the said anthraquinone compounds beingsubstantial- 1y free from impurities possessing affinity for acetaterayon.

5. A dyestuff preparation consisting of Water, a dispersing agent, andapproximately equal quantities or l-(fi-hydrcxyethyl)-amino-4-phenylaminoanthraquinone and l-methylamino-ephenylaminoanthraquinone in a finely divided and dispersiblecondition.

PAUL GROSSMANN. WALTER KERN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,967,772 Grossmann July 24, 19342,060,186 Felix Nov. 10, 1936 2,272,294 Finlayson Feb. 10, 19422,342,191 Grossmann Feb. 22, 1944

1. A DYESTUFF PREPARATION IN WHICH THE DYEING CONSTITUENT CONSISTSMAINLY OF A MIXTURE OF 1-(BHYDROXYETHYL) - AMINO-4-PHENYLAMINO -ANTHRAQUINONE AND 1-METHYLAMINO-4-PHENYLAMINOANTHRAQUINONE IN A FINELYDIVIDED AND DISPERSIBLE CONDITION AND IN RELATIVE PROPORTIONS RANGINGFROM ABOUT 4:1 TO 1:4, THE SAID ANTHRAQUINONE COMPOUNDS BEINGSUBSTANTIALLY FREE FROM IMPURITIES POSSESSING AFFINITY FOR ACETATERAYON.